A boy moves a body of 10 kg of mass, initially at rest, a distance of 5 m, pulling it with a force of 30 N parallel to the direction of displacement. The coefficient of friction of the body with the soil is u = 0.2. Determine: a) the work done by the boy, b) the work carried out by the friction force, c) the total work, d) the speed that the body has once it has traveled the 5 m